Herbicides are chemicals used to fight the growth of weeds in gardens and farmland. Herbicides are generally applied as sprays to soil or to the leafy part of weeds to kill the plant. Herbicides have several effects on the environment which should be considered before application.
Killing of weeds with herbicide changes the vegetative habitat of the sprayed area. This can change the environment for surrounding wildlife such as birds and mammals. These animals may rely on the treated vegetation for sustenance, and if it is eliminated the animals may be forced away or caused to starve. This is common with herbicides sprayed in forestry areas.
Herbicides are often toxic to animals and humans. The spraying of herbicides in large areas through the use of plane or tractor spraying can cause spreading of the herbicide to unintended areas. As the herbicide is in the air, it may drift beyond the intended spraying area. Those spraying the herbicides are in danger of poisoning themselves through long-term exposure if not using the proper safety equipment, such as respirator masks and safety glasses. Herbicides consumed with vegetation by animals can cause death and nerve damage to some species of animals.
Degradation of Land
Many herbicides are non-selective, meaning they affect plants and animals that were not intended as the target of the application. This can be detrimental, especially in forestry areas, as herbicides can destroy the biodiversity of the area by killing plants. Not only does this affect animal diet, but it may also ruin the soil of the area, as many plants prevent erosion and the leeching of nutrients from the soil. Bugs that are beneficial to the area may be killed as well. This may cause the natural checks and balances of predatory insects and their prey to become tipped, causing an infestation of bugs in the area.